Eric Smith wrote: The Coco had real crappy I/O hardware. This made it imposible to have a clean version of OS-9 with interupt driven hardware.

Tony Duell wrote: Just BTW, in case anyone is interested in the "inner workings" of the 6845, DP8350, 8275, 6545 or 5027 CRTCs, I've got a copy of Gerry Kane's "CRT Controller Handbook" here. Anyone got a copy of the book mentioned on the front cover, "An Introduction to Microcomputers: Volume 3 - Some Real Support Devices"? Also, has anyone got a timing diagram of the sync signal a Microvitec Cub 653 (as used with the BBC Micro) requires or a BBC Micro generates? I'm specifically interested in the pulse width of the Hsync and Vsync parts of the Csync signal and the high pulse width (visible area). Thanks. -- Phil. philpem(a)dsl.pipex.com http://www.philpem.dsl.pipex.com/ PGP Key ID: 0x0E18C95F PGP Key Fingerprint: 2741 5CB7 1D45 6F77 D1FC FA3D 7A87 2DA4 0E18 C95F

Tony Duell wrote: That would be great. Csync and red video would be even better if you can get the Beeb to display either a crosshatched red screen or a solid red screen. Otherwise Hs and Vs would be OK. Thanks. -- Phil. philpem(a)dsl.pipex.com http://www.philpem.dsl.pipex.com/ PGP Key ID: 0x0E18C95F PGP Key Fingerprint: 2741 5CB7 1D45 6F77 D1FC FA3D 7A87 2DA4 0E18 C95F

Tony Duell wrote: Fair enough. All of those please. MODE 7 would be OK. I need the timing info to connect a Teletext i/f up to the Cub, so MODE 7 (Teletext emulation) would be the logical choice. Thanks. -- Phil. philpem(a)dsl.pipex.com http://www.philpem.dsl.pipex.com/ PGP Key ID: 0x0E18C95F PGP Key Fingerprint: 2741 5CB7 1D45 6F77 D1FC FA3D 7A87 2DA4 0E18 C95F

Tony Duell wrote: Nope. The TTX board doesn't have a sync generator. Thanks. -- Phil. philpem(a)dsl.pipex.com http://www.philpem.dsl.pipex.com/ PGP Key ID: 0x0E18C95F PGP Key Fingerprint: 2741 5CB7 1D45 6F77 D1FC FA3D 7A87 2DA4 0E18 C95F

Tony Duell wrote: The board is from a Ferguson T14T (Thomson TX91 chassis?) and has two ICs onboard - a Texas Instruments IC labelled: EUROTEXT TELETEXT DECODER CF70204NW 59A5V3W The other one is also TI, labelled: 58D71DT CF72306 DATA SLICER Anyone got a Ferguson T14T or Thomson TX91 service manual? I need the part number of the TTX decoder mentioned in the schematic. I think it originally used a Philips SAA52xx IC, not sure though. Thanks. -- Phil. philpem(a)dsl.pipex.com http://www.philpem.dsl.pipex.com/

Tony Duell wrote: *ACK. There are Philips chips with built-in RAM, though. SAA5246 IIRC. The thing that seems interesting is that the TTX controller IDs it as an SAA52xx series TTX controller. The original schematic that I had (a VERY bad scan) listed the TTX controller as an SAA-something-or-other. Shame the scan was so bad. I'm not sure the chassis was TX91 anyway - it might have been TX90. Same thing. Ferguson=Thomson, T14T=TX9-something. Later. -- Phil. philpem(a)dsl.pipex.com http://www.philpem.dsl.pipex.com/

Tony Duell wrote: Oops - my bad. I think the SAA5281 has the RAM integrated, IIRC. The I2C address is the same as some of the chips from the SAA52xx series. I'm planning to build a video generator using a PIC and then connect Sync to the Cub653, CVBS to the TTX board, then connect R.G.B. from the TTX board to the monitor. In theory that *should* get me a picture. I've got an I2C interface for my laptop that still works, so I have some way of controlling it. Later. -- Phil. philpem(a)dsl.pipex.com http://www.philpem.dsl.pipex.com/

Tony Duell wrote: Hmm... I thought it used the CVBS signal to lock onto and then generated RGB video out. RGB -> Cub monitor, Sync from vidgen -> Cub monitor, CVBS from vidgen -> TTX board. Anyway, I'll see if my PICDREAM video generator can generate a good enough signal for the TTX board to generate some form of video signal. The 5281 also seems to allow access to its RAM via I2C register accesses - set the X and Y co-ords, then write a character to it. Oh, how I wish I had a TX91G service manual so I could find out just how this pesky thing works and what Thomson originally designed it to use... The TX90 uses an SAA5281, the schematic I've got for the TTX board has had the "SAA52" bit nipped off and most of the next digit. It looks like a 2-chip design, though. *thud* *thud* *thud* *thud* <-- sound of philpem's head hitting the wall many times... Know anyone that stocks the SAA5243? Can't find it on Farnell's site, nor does my CPC catalogue list it. [snip] Actually, mine uses a 7406 (IIRC) buffer. It's a clone of the original Philips I2C probing pod. It looks like it can intercept I2C traffic and also output it. I'll see if I can persuade the TTX board to generate any video tonight. I've got a Tek 466 storage scope and a Gould OS1100A in case I need an extra two channels. Anyone know of a source for Tek 1x/10x probes? The 466 seems to want the ring around the BNC connector shorting to the shield (GND) to push it into 10x mode. Guess how many probes I've found that do that... That's right, none. Later. -- Phil. philpem(a)dsl.pipex.com http://www.philpem.dsl.pipex.com/

Tony Duell wrote: [snip] I don't WANT it to decode PAL. I'm using it for a display system in a selfbuilt computer. I'm going to add a video tuner later (i.e. when I've reverse-engineered one of the VCR tuners in my junk^M^M^M^M quality used parts box). That's the mode I'm planning to use it in. I don't want it to generate a TTX data stream. I want it to generate a video signal for the TTX to lock onto and the Cub to sync to. I don't care if it has no TTX data to lock onto - I can just load its RAM and send it a "DISPLAY ON" command. Might be worth a shot. Thanks. Now, I wonder if the central library is open on a Saturday... I think I've got the MCU somewhere. Don't know if it still works, though. Ooh - another company to track down :-) Time to track down a junked ICC5 chassis. Anyone on here got one they don't mind pulling the Teletext board out of? :-) Ah, right. So it doesn't matter if I use, say, a Velleman "professional" 10x probe and leave the outer contact unconnected? Or I could just shove a piece of tinfoil in there to short it out... The 466 seems to support 1x/10x only. No OSD either. The trace does look a bit "grainy", but I guess that's because it's a storage scope. BTW, anyone interested in a Gould OS1100A? 30MHz, delay sweep, single timebase, dual channel, no manual, a bit heavy. Make me an offer - buyer collects or sends a courier round for it. Later. -- Phil. philpem(a)dsl.pipex.com http://www.philpem.dsl.pipex.com/

Philip Pemberton wrote: We have a copy of this in the library at work. This is a large collection of datasheets and descriptions, loose leaves in a binder that was obviously meant to be extended over time. I think it is by Gerry Kane and Adam Osborne, but I can get you a full citation and description later. - Paul

Paul Williams wrote: I already have the CRT controllers book, so this one is now on my list of books to find on AbeBooks.com! Thanks for posting the details. Just recently, I found a 1966/67 edition of The Digital Logic Handbook, which describes all the flip-chip modules of the time. Also shows the PDP-7 and PDP-8. At the same bookshop, I found a copy of the TTL Cookbook, by Don Lancaster and the Scelbi 8080 Software Gourmet Guide. -- John Honniball coredump(a)gifford.co.uk

----- Original Message ----- From: "Dan Veeneman" &lt;dan(a)ekoan.comTo: &lt;cctalk(a)classiccmp.orgSent: Monday, September 09, 2002 4:39 PM Subject: DEC Logic Handbooks, was Re: 6845 CRTC, Microvitec VDU/BBC Micro sync waveforms PDP-11." I've got the Logic Handbook from '73 - '74. It has sections labeled: Logic & Control Computer Interfacing Analog Modules Accessory Modules Dec Kits Power Supplies Cabling Hardware Data Entry Terminals Lab Series The "Computer Interfacing" section has a picture at the front of a lady with late 60's or early 70s hair looking at a Teletype printout. Clearly visible in the picture is the frontpanel of a PDP-8/I.